Phenotypic variation of a selection of safflower (Carthamus tinctorius L.) lines and their potential in southern Australia

 Wachsmann, N.G., Knights, S.E. and Norton, R.M.

 Abstract

The potential of 18 safflower (Carthamus tinctorius L.) lines for adaptation to southern Australia was evaluated in a glasshouse experiment.  The lines tested included Australian cultivars, Australian breeding lines, overseas cultivars and hybrids.  The lengths of various phenophases were recorded in days and growing day degrees (GDD).  The potential of these lines to match the climatic limitations imposed on southern Australia’s cropping systems was considered.  The experiment showed a range of 26 days (216 GDD) for flowering on primary branches between the earliest and latest line.  In the field, this additional 26 days of evapotranspiration would be desirable where dewatering benefits the rotation, but could be detrimental to the safflower crop in dry environments.  Early maturing lines e.g. UC-1 (104 days; 704 GDD to flowering on primary branches) are likely to be adapted to drier environments where limited water late in the growing season prevents long season lines from maturing.  The ability to sow short season lines in late spring allows the use of cultivation and broad-spectrum herbicides for weed control during the autumn/winter period and so provides a means for controlling weeds resistant to selective herbicides.  Late maturing lines e.g. 120043 (130 days; 920 GDD to flowering on primary branches) would be better suited to higher rainfall environments or where soil profile dewatering is required.

 Key words: safflower, phenology, adaptation, water use, tactical crop